The invention relates to a piston for internal-cumbustion engines, more especially diesel engines, which is provided with a piston barrel consisting of light metal and a head plate which consists of a metal having a lesser thermal conductivity but a greater high-temperature strength, for example steel, and which is fastened thereto with the aid of retaining screws, which extend parallel to the piston axis, and are preferably designed as expansion screws, and which is supported against the piston barrel only by a ring shaped rib, along a narrow ring rib through which the retaining screws pass, and in which piston a radially outwardly widening gap is left free between the opposite faces of the ring shaped rib formed on the head plate and the ring rib of the piston barrel at room temperature and when the retaining screws have not yet been tightened.